LGD

A
STUDY ON CONTROL
DISCHARGE TOILET SYSTEM
BY
G BHAVANI PRASAD
SSE/NC/LGDS
INDIAN RAILWAY CONFERENCE ASSOCIATIN
NEW DELHI
1

ACHNOWLEDGEMENT
I am very much glad to NCO/IRCA/NDLS who has extended
his great support and valuable suggestions in completing this
technical paper presentation
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INDEX
Page No
ABSTRACT 4
1) Introduction 5
2) Salient features of CDTS 5
3) Main suppliers of CDTS 5
4) Working principle of CDTS 6
5) Major components of CDTS 7
6) General operations of CDTS 9
7) Testing procedure of CDTS 10
8) Modifications Suggested 11
9) Conclusion 11
3

ABSTRACT
The main purpose of this technical paper is to
study Control Discharge Toilet System, its
purpose, working principle , parts , testing and
some modifications in the system.
4

1) INTRODUCTION
The basic purpose of introduction of Control Discharge toilet system in
Indian Railway is to eliminate the practice of spillage of toilet waste on to
railway station area & in the populated area of city.These toilet systems are
designed to operate on the principle of high - flush through which the
evacuation of toilet bowl is carried out by means of water pressure. It operates
with a pressurized water bowl wash that covers 100 % of the toilet bowl area.
The toilet waste is transferred to the retention tank with a control amount of
water.
2) Salient feature of control discharge toilet system:
It’s easily programmable and reprogrammable
Less Air, Water and electricity
Fully P.L.C Controlled.
Easy to clean.
Hygienic, improves environmental conditions at Railway stations.
3) Main suppliers of CDTS
(a) M/s Aikon Technologies Pvt Ltd.
(b) M/s Vibhu Composite works.
5

4) Working Principle Of CDTS
This system works on electrical & pneumatic pressure arrangement. The
retention tank which stores effluent has two openings. These two openings
activates by double acting pneumatic cylinders fed by Feed pipe of air brake
system. Upper opening opens every time the user operates the flush button,
whereas lower opening at predetermined speed & after predetermined no. of
cycle of flushes. The solenoid/magnetic valves control the entry of pneumatic
pressure in pneumatic cylinders attached to openings/slides.
The pressurizer provided in CDTS system, delivers pressurized water to flush
the waste. The logical control records the no. of flush cycles as well as speed of
the vehicle through WSP System to operate the lower opening to drain out the
effluent.
Schematic Diagram of CDTS
Figure 4.1
6

5) Major Components of CDTS
1. Indian & European toilet basin with flush nozzles:
There are two types of toilet basin used in these CDTS system. These
toilet basin bowls made up of Stainless Steel AISI 304 with upper side
pickled & grinned
2. Control panel:
Control panel consists of following equipments:
Programmable logic controller (PLC):
Solenoid valve:
Control relay:
3. Retention tank:
7

4. Flapper Valve:
Flap
Flapper assembly
5. Lower Slide valve:
6. Flush button:
7. Water Pressurizer:
8

6) General Operations of CDTS
1)Stand-by condition
2)Flush Cycle
3)Retention Tank Discharge Cycle
1)Stand-by condition
Water Pressurizer – Off
Water check Valve – Closed
Upper Flapper Valve – Closed
Lower Slide Valve – Closed
2)Flush Cycle
Step – 1
Water Pressurizer – On (for a predetermined time)
Water check Valve – On (for a predetermined time)
Upper Slide Valve – Open (for a predetermined time)
Step - 2
Water Pressurizer – Off
Water check Valve – Off
Upper Slide Valve – Closed
3)Retention Tank Discharge Cycle
Condition – I
Condition – II
If train speed is - below 30 kmph then the retention tank
lower slide valve – closed.
If the train speed is above 30 kmph and Flush Count is
below Predetermined value, then the Retention Tank Lower
Slide Valve remain closed
If the train is above 30km/h and Flush Count is equal or
above Predetermined value, the Retention Tank Lower Slide
Valve Opens (for a predetermined time).
End of Retention Tank Discharge Cycle
Flush Count restarts at ZERO (0)
9

7) Testing procedure of CDTS
CDTS DEMONISTRATION STAND
Figure 7.1
AUTO PULSE GENERATOR
Figure7.2
Figure 7.1 shows a Demonstration stand on which the testing of CDTS can be
demonstrated . Connect the auto pulse generator as shown in figure 7.2(this pulse
generator is approved by EDME/chg/RBLr.No.96/M( C )/137/33 VoL.II Dt:
27.09.2010 ) to the PLC and provide necessary inputs like electric supplies to all
electrical components like solenoid valve, PLC, AC-DC convertor and water
pressuriser. Connect the air pressure to the inlet of the demonstration stand. After
giving all necessary connections press the flush button for some pre-determined no of
flushes. For every press of flush button the upper flapper valve gets open for some
pre-determined seconds. After completion of pre-determined flushes increase the
speed of vehicle ( here the corresponding pulses ) from 0 to above 30 kmph . After
attaining the speed above 30 kmph the upper slide valve gets open for pre-determined
seconds and closes .this is how the CDTS can be tested for it working.
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8) Modification suggested
Presently the connection between Toilet Bowl and CDTS Retention
Tank is a straight pipe if that Straight pipe is replaced with a ” P ” Trap
then the following advantages may be attain
1) Bad smell can be avoided as the water accumulate in the “ P ”
Trap will act as an insulator
2) Avoiding of entering the materials in to the Retention Tank like
Bottles, cloth etc.
The water flow diagram in “ P ” trap and some example are shown in
figure 8.1, figure 8.2 subsequently.
Water Flow Diagram of “ P “ Trap
Figure 8.1
“ P ” Trap
Figure 8.2
9) Conclusion : studied working principle of the control discharge toilet
system, its parts , analysed how to test the control discharge toilet system
and with suggesting some modifications.
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